As physical fitness becomes more popular, many attempts have been made to design exercise machines to imitate free-weight exercises. Exercise machines attempt to provide the benefits of an exercise traditionally performed with free-weights, while minimizing or eliminating the hazards of free-weight training. Exercise machines sometimes allow an exerciser to gain more benefit from an exercise than he would by performing it with free-weights. The most important free-weight exercise subject to being modeled by a machine is a lower-body exercise known as the deep knee bend, commonly referred to as the "squat." The squat exercises mainly, but not exclusively, the lower body and is important because it involves the body's biggest muscle groups, thus enabling an exerciser to build maximum strength and muscular size.
Traditionally, the squat exercise is performed with a weighted bar held across the exerciser's shoulders and behind his neck while squatting into a crouched position. The exerciser completes the exercise by standing up, all while steadying the weight bar.
The squat greatly benefits the thigh muscles of the exerciser. It has been shown that additional whole-body benefit is obtained by performing shoulder shrugs while in the standing position, especially during high repetition sets. Good form, especially keeping one's upper body reasonably upright, is necessary to obtain the desired benefits from the squat exercise, and also minimizes the physical hazards associated with it.
As commonly performed, the traditional squat exercise has several disadvantages, both physical and practical. The physical disadvantages relate to poor exercise form, which causes excessive strain on and often injuries to the knees and lower back of the exerciser. Knee strain is a result of improper orientation of the exerciser's lower legs with respect to the exerciser's upper body during the performance of the lower, and far more dangerous, half of the squat exercise. Ideally, the exerciser's lower legs and upper body should remain substantially parallel to each other during the performance of the lower half of the squat exercise, thus keeping the exerciser's knees substantially directly above his feet, and much more stationary, thereby minimizing knee strain. However, during the traditional squat exercise, the lower legs and upper body are usually not parallel during the lower half of the squat exercise, causing the exerciser's knees to move too far forward, which increases knee strain and the risk of injury.
Another physical danger is lower-back strain, which results from the exerciser leaning too far forward during the squat. Leaning too far forward can cause a condition known as lordosis, or "swayback," and serves only to exercise mainly the exerciser's hip muscles much more than his leg muscles.
One practical disadvantage relates to the need for an assistant, or spotter, when performing a squat, in case the exerciser should be unable to complete his last repetition and become stuck at or near the bottom of the exercise. Another practical disadvantage relates to the range of motion able to be performed during a typical free-weight squat. The exerciser is often limited to how low--i.e., how fully--he can squat safely due to improper exercise form, poor design of the apparatus and to other physical limitations. A further practical disadvantage is the fact that during a free-weight squat, the exerciser cannot easily stop, and subsequently resume the exercise conveniently and safely. Typically, to finish a set of free-weight squats, the exerciser must remove the weight bar from his shoulders and set it onto the floor or place it onto a squat rack.
Many squat machines have been developed to attempt to alleviate the problems and limitations associated with the traditional free-weight squat exercise. Typically, machines that have been designed to duplicate or improve the squat exercise either have the exerciser lying in a recumbent position in order to displace resistance away from his body, such as a sled or leg press, or have him oriented in a vertical or slanted position with his feet engaging the floor to press his body weight and any associated extra weight upwardly along a rail or guided path.
Many of the current squat machines have addressed some of the problems associated with the free-weight squat exercise, but have not alleviated certain other important problems. Certain dangers and limitations are still encountered by the exerciser when using these machines. For instance the exerciser's lower legs and upper body are prevented from achieving and maintaining the necessary parallelism during the lower half of a machine squat, thus aggravating knee strain and raising the risk of knee injury, as discussed above. Current machines also continue to aggravate lordosis. Furthermore, most of the machines do not enable the exerciser to stop the exercise at any of a plurality of positions to facilitate exiting the machine, or in case the exerciser becomes stuck in an awkward position. Also, current exercise machines orient the exerciser's legs so that the exercise is more of a hip exercise than a leg exercise.
Given the importance of shrugging against the available resistance at the top of each repetition of squats, another major limitation of current squat machines is that their flat, stationary backpads prevent the exerciser from performing shoulder shrugs. Typically, in squat machines utilizing a carriage which moves through any guided trajectory, the exerciser's feet are on the floor or a platform, and his shoulders engage shoulder-pads while his back typically engages a flat, stationary backpad. The squat exercise is performed by the exerciser pushing the carriage away from the floor by straightening his legs to apply a force primarily against the shoulder pads and to some extent against the backpad, thus raising the carriage, his own body weight and any additional weight loaded onto the carriage. At the top, or standing position, of the squat exercise, the exerciser ideally would perform a shoulder shrug. The combination of the shoulder pads and the flat backpad inhibits the breathing of the exerciser, as well as the actual movement necessary to perform a shoulder shrug. In addition, the more recumbent the position of an exerciser's upper body in a squat machine having a flat, stationary backpad, the more heavily his body weight presses against the backpad, which further impedes the shrugging exercise and the essential deep breathing necessary for the shoulder shrugs and for performing many consecutive repetitions.
The shoulder shrug has been shown to provide excellent additional muscle growth benefits when performed during a high repetition set by causing the exerciser to become fatigued more quickly. A properly performed squat is much more effective at building an exerciser's legs than is a leg press or a leg extension exercise, and intermittent shrugging during the same set makes it even more effective than squats alone would be.
Another shortcoming of the currently available squat machines is that they often allow a less than full range of motion due to the fact that the exerciser's feet engage the floor, or a platform that is too close to the floor. Regardless of how well a squat machine maintains the lower leg/upper body parallelism required to minimize knee strain, the maximum exercise benefit is obtained when the exerciser can perform a full-range squat without any limitation on the lower end of the lower half of a full squat exercise.
It is to overcome the shortcomings in the prior art that the present invention was developed.